"Still, I mean, it's a disgrace. Here we are, two years later, and the cops are totally incompetent," he is heard saying, adding: "The idea that the cops then started coming after you, kick you out of bed, and your families, at six in the morning, is unbelievable."

He also is heard saying: "But why are the police behaving in this way? It's the biggest inquiry ever, over next to nothing."

Mr Murdoch is heard adding: "And now they're arresting their own, who never even took money... They're going to put all newspapers out of business."

The recording of Rupert Murdoch was reportedly made at The Sun's base in Wapping, east London. Credit: John Stillwell/PA Archive

Rupert Murdoch has been heard condemning police who are investigating alleged phone-hacking and illegal payments to officials by his journalists as "totally incompetent" in a secret recording broadcast by Channel 4 News.

The News Corp boss is heard apparently regretting the amount of information his company had handed over to the investigation - describing it as a "mistake" - while also appearing to tell staff who feared losing their jobs if found guilty of any offences to "trust" him.

The recording, obtained by the Exaro investigative website, was said to have been made in March during a meeting with journalists from The Sun at his newspapers' headquarters in Wapping, east London.

A spokesman for News Corp told Channel 4 News: "No other company has done as much to identify what went wrong, compensate the victims, and ensure the same mistakes do not happen again.

"The unprecedented co-operation granted by News Corp was agreed unanimously by senior management and the board, and (News Corp's management and standards committee) the MSC continues to co-operate under the supervision of the courts.

"Rupert Murdoch has shown understandable empathy with the staff and families affected and will assume they are innocent until and unless proven guilty."

Mr Murdoch praised the former Prime Minister's role in facing down the trade unions in the 1980s and said the Government made it possible for News International to survive a year of industrial action fighting against a move of operations to Wapping, East London.

Rupert Murdoch. Credit: Lionel Hahn/ABACA USA

The tycoon wrote in The Times (£): "Mrs Thatcher understood that risk was a vital ingredient in a free enterprise society. She understood that such a society had to be led by a government with backbone.

"After the Second World War, in which the country lost a second generation of its finest men, Britain had created a dependency state. It killed off aspiration.

"In 1979 Margaret Thatcher set about its rehabilitation. She put the economy on a sound footing, she ended a culture of crippling strikes, she encouraged entrepreneurs to come here and set up their businesses.

"Thanks to her I have experienced in Britain many of my defining moments as a businessman, a Britain that is far more successful as a result of her brave leadership."